"Nautral" canine model of infantile hydrocephalus.

A review of the current knowledge about a variety of aspects of infantile hydrocephalus suggests that one cause of this problem is subarachnoid blood from birth trauma interacting with an anatomically immature cerebrospinal fluid-absorbing system. To test this hypothesis and to create a model that could be used to devise various methods of prophylaxis and therapy, we injected autologous blood into the cisterna magna of puppies, followed the size of their ventricles with serial computerized tomographic (CT) scans, and evaluated the scanning electron microscopic (SEM) appearance of the ventricular walls and subarachnoid space. By injecting blood until the dogs were just at the point of apnea, we obtained a 46% incidence of hydrocephalus with a 13% mortality rate. The amount of blood accepted was variable. The size of the ventricles was followed with CT scans; the time course of hydrocephalus was variable, and in some cases it resolved. SEM revealed significant regional, free cell aggregation and calcification, especially over the base of the brain, which was most marked in the animals that developed hydrocephalus. This suggests a more marked reaction or a lesser ability to clear the subarachnoid blood in those animals, although the reason for this is not clear. Possible uses for this model are suggested.